EU261/2004-prescribed compensation is due from the operating carrier. Is it possible they're on the AF-operated CDG-ATL flight? (edit) Pseudo-confirmed. Flightstats shows a long delay on AF 688 today.
A hotel voucher, if necessary due to a forced overnight in ATL, will be provided in ATL.
Mech delay out of CDG/compensation? would be a more descriptive thread title.